Applied patch from Srinivas Vutukuri to have tx_samples accept -g

Applied patch from Srinivas Vutukuri to have tx_samples accept -g

Date: Tue, 19 Jan 2010 18:15:08 +0530
From: srinivas naga vutukuri <srinivas.vutukuri@gmail.com>
To: discuss-gnuradio@gnu.org
Subject: [Discuss-gnuradio] tx_samples.cc is not accepting the gain
	 parameter input.
Hi,

I observed that tx_samples.cc is not accepting the gain input parameter
(ie., -g option). I just changed like this in my code.
Its working, so posting the changes. If it is acceptable please take it.

best regards,
srinivas.